H(infinity) controller design based on steering structure for front-wheel-steered vehicles

Abstract

This investigation proposes two stability and lane-keeping unmanned control structures (UCS) i.e. UCS I a nd UCS II in front-wheel-steered (FWS) vehicles. This work achieves the following objectives 1) accurate steering of wheels accurately minimizing system errors of the lateral position, the handling angle and the yaw rate and 2) maintainin g a smooth ride quality with different forward velocities and loads. Each of the two steered systems has a control tracking the desired course: a double lane change maneuver (DLCM). The designed controller based on the H(infinity) algorithm, th e linear matrix inequality (LNU) technique, is developed and applied. It is found that each steering structure has a robust controller which is capable of keeping the vehicles in the designated lane. For safety and improved car handling, FWS vehicles require a structure to monitor either the lateral displacement (gamma(L)) together with a handling angle signal (phi) for UCS I or a lateral displacement (gamma(L)) and a yaw rate signal (gamma) for UCS II, as evidenced by the theoretical analysis and also employ a look-ahead formulated controller. Numerical simulation conforms that good vehicle performance is achie ved using the controller.